This is very much an initial release and I know there are things that need improvement, though I'd greatly appreciate feedback to help figure out what those improvements should be.

We've tested this new UI on the iPhone, Android 2.x, BlackberryOS 4.5 and 5.0, Kindle 2.5 and in a number of desktop browsers.

Once you install the extension, you can have a look around from your desktop browser by visiting /m on your RT server. The Mobile UI tries pretty hard to detect mobile browsers and push them to the mobile login page, though there's a link to get back to the full UI if it gets your browser wrong.